Scissors, shears, and the like



Feb.. 25, 1930.

`J. H. c. BOYD 1,748,701

SCISSORS, SHEARS, AND THE LIKE Filed June 1.2, 1928 Patented Feb. 25, 1930 g UNITED 1 STATES plfA'l:ENTAGFFICEr f v r'AMEs HENRY GAETNEE Boxn,Y on sAL'i` HILL; sLoUGH, ENGLAND soIs'soIvsQ s'HEARs, AND "rHE LIKE ,a

Application led June ,12,

' This invention relates AtoV scissors, shears `'and the like provided with detachable cutting l provide a design such that the manufacture of the blade is reduced to very s iinple operal tions. v f v To these' ends, and in accordance with the' 15 present invention, a bladegwhich consists of a thin Inetal plate 'formed with an inclined tongue and a cut-away portion as described in Y my said prior patent is formed also with a substantially concave surface transversely of 20 the blade and extending from about the pivot to the tip of the'blade, whilst that portion of the blade extending from about said pivot to stantially convex surface transversely there,-y

25 of Y The'concave and convex surfaces above rei Vferred to may be produced in any convenient` manner as by grinding, stamping, pressing, *30 rolling, or any other convenient manner.

erence to the annexed drawings, wherein Figf ure 1 is aface view of a blade in accordance with the present invention. vFigure lffl is a central longitudinal section thereof, theV thickness being shown to an exaggerated scaley for the sake of clearness Figuresv 2 and '3 are respectively enlarged sectionson the lines 2--2 and 3-43, Figure 1. Figure 4 is a si1ni`V lar view to, Figure 1, showing the blade as fitted to one carrierofa pair of detachabler blade scissors. Figures and 6 are respectively, enlarged sections on the lines 5-5 and 6 6, Figure 4. Figure l7 is a section of a blade portion of substantially concave-convex form in cross section whilst Figure 8 is a similar viewv showing such a blade in position on a carrier, and Fi reV 9vis la cross section of the `heel portionof a' bladeof substantially concavo-convex formreversely similar to that '50 shown in Figure 7 it being understood when as described in myrjsaid prior patent.,A

formed with a substantially convex surface'A The invention will be described with refcarrier-'.19' of :pair Of SCSSOTL` suhfcarrier. being provided with a back11g"20 adaptd'to 1972s. serial No. 284,771".

the'terins concavo and c'onvex areused in this specification, that suchidenomination is givenl with respect `to a plane extending nor-r p mal to that ofthe material during the cutting operation.

. Y- f y 55 The blade, shown inzFigure 1consists ofa 'thin steel-plate 10 yformed with a bevelled cutting edge 11, a locating tongue 12, anda pivot hole 13, and cut-aw'ayfat the back as at all .v

The surface of thatportion ofthe blade extending between the pivot holeulan'd the tip 15 of the-blade is brought in anyconvenient mannerto' concave form'as shown at 16 in Figures '1% and 3, the effectof such concavity" 65 being to facilitate greatly the'cutting operation by preventing contact Y,between the whole Y' of the .adjacent surfaces o'ffa pair of blades during the lcutting operation',^as in the pres-v ent casethe'friction is reduced because con-`v 70 Y, vtactbetween the bladesis limited to a'rela- 'p tively sniall area adjacent to the cutting-edge. v i the heel end of the blade is formed with a sub- That portion of the blade extending from the pivot hole '13 to 'the ,heel portion-1 7 is' 75 l18 as shown,"partic`ularly in Figures land 2, the 'convexity of such heel portionbeing of a height greater than the thickness'f of theblade between the pivot hole 13 and the tipl, and` having for effect, when theblades arebrought 0 togetherf duringY the cutting operation, and providedv there is suiicient play for suchmotion between thepivot hole 13` and the pivot Iitself {(n'otshown) aswill cause 'the convex, .portion Q18 on one bladetoride on, orco-act with, the' ,corresponding convex portion', on the other blade, in such -a manner that relative tilt of the' blades will result, whichfwill throw'the cutting edge of one blader against Q the cutting edge of the jother and ,disengage the .trailing 'edges ofsu'ch blades,k thus assisting considerably in the cutting operation by,`

reducingy ythe* great amountofjfrictionfwhich would arise were the blades fiat orwere they, of a shape such that frictionV would be liable 5 to take place vthroughouty they width`l ofthev i .'InjFi'gure L1.7Ythefblade'y10 is shown' on one tialfor the purpose above deseribeCL- tliat i the surface of this portion should be convex, Figure illustrating the relative positioning 5 of the blade 10, carrier 19,"and'backingwvall 20, onthelineigure 4,Whilst Eigure .x

-`gg consisting of "a strip df steel`,ornfl'edfgvvithA a flat c under-surface 21 adapted "to vlie 'against ,jasimilar.,flatgsulfalbfi tll'eiorespqndins paniek.. t.

" 'lheeoncave andconvex snriiaceslniaype .also ,sary, fhestrjpmay" betsflafrad, Pressed; .0r

rolled, `until yit is, of a ,gross ,sectional .eheufafen @.Prrespondinaapproximately jvitli. thoseishown in Figures 'lgand 2,'` after V Y'yljlfcil-i a ,very slight grin'dingfoperation. only 35, is'nec'essary to bring the,v surfaces' ,toftliefde-Y sired Cl-ijfgljee of inishto givethebf:estf cutting ledge, ,i't' Abeing' undertgsjodlthat, .the actual ,cli'bmfer fon the. cutting edge {11 would be produeedlin' the ordinary nuanner.

iba-conti K A van'oftheny lade When the` Complete,*scissorsi are assembled, a substantially gconcave, 1surface Figures 7 andSillustrate af niodiiedform Y upper surface of the blade being concave substantially' from said pivot hole to the tip and convex substantially from the pivot hole to the heel, for the purpose described.

2. A detachable blade for scissors, shears and the like, consisting of a. thin metal blade ornied, at itsuopposite endsl with a tip and a heel and near said lheel with a pivot hole,

the cr'sslseetinal Configuration of said blade varying progressively in area and shape from the, tip tOLhe heel,A one :side of allsuch crossseet'ions, from the tip to about the pivot hole being concavel and the corresponding side .Ot all sueherossfsections from the heel to about the pivot hole being convex, the blade presenting'L at that part thereof, which 1.Will 'uousvvith the corresponding par@ ,0f

merging. into a substantially ,convex surface,

Ethe" point, of,merge11C@A beingl Asubs,tantially at `pivot hole, substantially as, described.

,I 3. .,A. detachable blade for scissors,r- ,shears andfthe'like, as claimedin .claim 1, wherein the Aconcave and lConvex ,surfaces are: rornned vonfastrip forined'lwith convex andreoncave with the concave andl convex upper surtaces,

` substantially as Y, described.

GAM-mlsL BOX@- vdes'efribedwith,referene to :Figure 3Q@ eletr "thel `portion Lof the,v blade, between@ the fPVOt and@ 113, pdrfthetip. .1e/is rsplaqeci byl agonsmania al .Iisiir- Ircimfg- 1'.Y 'I detachable 'blade for, seissiorsa shears 

